As tourists, we followed signs for parking in this...

As tourists, we followed signs for parking in this area, in the interest of walking to Willis Tower. After the confusing blur that was parking, we found ourselves on foot at the street level. We gazed up at the massive structure to memorize the location and later retrieve our vehicle. Chicago Mercantile Exchange? Really? How did we end up parking, as tourists, in the basement of the largest options and futures exchange in the world? Well Terry, thanks for the hospitality! It was a very convenient location!